Reactive Transport Mechanism for Organic Oxidation during Electrochemical Filtration: Mass-Transfer, Physical Adsorption, and Electron-Transfer Supporting Information Journal of Physical Chemistry Revised November 28, 2011 Han Liu and Chad D. Vecitis* *
Corresponding author: Chad D. Vecitis, Email:
[email protected], Phone: (617) 496-1458. Address: School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
Figure S1. Electrochemical filtration apparatus. A) Design of the modified commercial polycarbonate filtration casing consisting of 1) a perforated stainless steel cathode, 2) an insulating silicone rubber electrode separator and seal, 3) a titanium anodic ring that is pressed into the carbon nanotube anodic filter, and 4) the MWNT anodic filter supported by a PTFE membrane. B, C) Images of the modified filtration casing. D, E) Images of the MWNT network before and after electrochemical filtration, respectively.
1 (-)
Influent
+
2 1
−
SS 3 Cathode
e-
e-
1 2 3 4
B
Effluent A
3 (+)
D
C
4
4
Prepared Anodic Filter
Used Anodic Filter
E
Figure S2. Effect of temperature on dye adsorption to the CNTs. Adsorption used 0.015 g CNTs, V = 100 mL, and allowed for 24 h to reach equilibrium. The points are experimental data and lines are fits to the Langmuir isotherm.
-1
Sorption amount (mg g )
40 35 30 25 20 15 o
15 C o 25 C o 35 C
10 5 0 0
50
100
150
200
Equilibrium concentration (µM)
250
Table S1. Langmuir Isotherm Parameters for MO Adsorption onto CNTs. Langmuir constants A
T
Thermodynamic parameters B
b
qm
(L mg-1)
(mg g-1)
15
2.81
32.2
0.977
-35.6
25
2.33
28.5
0.983
-36.3
35
2.07
25.3
0.996
-37.2
(oC)
A
R2
qe = qmCe/(1/b+Ce) ;
B
∆G°
∆H°
∆S°
(kJ mol-1)
(kJ mol-1)
(kJ (mol·K)-1)
-11.2
0.0845
∆G° = –RTlnb ∆G° =∆H° - T∆S° 35
